物流配送最短径路的动态规划方法研究

确定物流配送的最短径路是提高物品时空价值的重要环节.在借鉴国内外一些研究成果的基础上,以动态规划理论为指导,选择合理的最优值函数及其自变量,列出递归关系式,并用标号法对实例进行验证.应用动态规划研究物流配送的最短径路,思路清晰,方法简便.     

中国电视业市场结构实证分析

本文实证表明,全国电视市场结构为以中央电视台为主导、集中度较低的寡占Ⅳ型市场结构;全国卫星电视市场为以中央台为寡头、集中度很高的单寡头垄断市场结构;省级城市电视市场以多寡头垄断为主,有些为双寡头垄断市场结构;地市级电视市场也以寡头垄断型为主,在经济较为发达的地市,有些呈现出以地市城市台为主导的寡头垄断市场结构.     

农业地区产业结构调整的偏离份额分析——以黄淮地区为例

作为农业大省的传统农业区域,黄淮地区产业结构经历了深刻的变化,其经济增长已不单单依靠农业支撑,伴随着地区工业化、城镇化的推进,更多的依赖于工业、服务业.因此,借助偏离份额分析模型,对黄淮地区产业结构和产业竞争力进行了研究,在此基础上,明确黄淮地区产业结构调整方向,确定产业发展重点,为加快黄淮地区产业结构优化升级提供理论支撑.     

Function approximation for incompletely specified regression models

This report extends earlier work by Brailovsky on regression theory and methodology, giving particular emphasis to function approximation for incompletely specified models. The interest here is with situations where the form of the regression relation is not known in advance. We discuss several difficulties that arise in using local approximation and linear regression methods, and propose ways to overcome these problems. To aid the data analyst in developing a suitable model, an illustrative table is derived for determining the number of initial explanatory functions justifiable for a given prespecified confidence level. The general approach formulated here is illustrated with an application to medical data. Relevance to classification and possible extensions are discussed.     

Error rates in quadratic discrimination with constraints on the covariance matrices

In multivariate discrimination of several normal populations, the optimal classification procedure is based on quadratic discriminant functions. We compare expected error rates of the quadratic classification procedure if the covariance matrices are estimated under the following four models: (i) arbitrary covariance matrices, (ii) common principal components, (iii) proportional covariance matrices, and (iv) identical covariance matrices. Using Monte Carlo simulation to estimate expected error rates, we study the performance of the four discrimination procedures for five different parameter setups corresponding to standard situations that have been used in the literature. The procedures are examined for sample sizes ranging from 10 to 60, and for two to four groups. Our results quantify the extent to which a parsimonious method reduces error rates, and demonstrate that choosing a simple method of discrimination is often beneficial even if the underlying model assumptions are wrong.The authors wish to thank the editor and three referees for their helpful comments on the first draft of this article. M. J. Schmid supported by grants no. 2.724-0.85 and 2.038-0.86 of the Swiss National Science Foundation.     

Mechanisms functional underlying the characteristics structural and of acupoints

Acupoints are particular areas on the surface of the body through which the Qi and blood of the Zang-fu organs and meridians flow. Acupoints can respond to stimuli and reflect syndromes. Research on the essential morphology of acupoints has two key focuses： anatomical structure and physiological func- tion. The structure is the material and anatomical basis for the function, while the function is the manifes- tation of the structure. The two factors not only have profound significance for our understanding of the essence of acupoints, but also have great value for clinical acupuncture and moxibustion practice. Based on the structural and functional characteristics of meridians under different physiological and pathological con- ditions, this paper illustrates the essence of acupoints and explores the rules and biological basis of the acu- point functions induced by acupuncture and moxibustion.     

梁启超小说功能观之利弊谈

自古以来,“小道观”制约着小说创作和小说理论的发展。直到近代,梁启超提出“小说为文学之最上乘”的理论思想,小说的地位才得以提高。然而这一著名论题,亦有偏颇不足之处。     

海南岛主要的自然因素与社会因素的关系分析

在社会的发展过程中,自然因素与社会因素(社会经济建设和社会问题)的关系是,自然因素提供社会经济建设的物质基础,是经济发展的前提条件,而经济发展带来的社会问题却反过来束约其本身的发展和自然因素的利用方式和途径。为了更好地理顺海南岛的自然因子与社会因子的关系,有助于海南开发建设,本文从发展与演变的角度进行具体的海南岛自然因子与社会因子的质和量的关系分析。文章的主体有一、人口的分布格局与发展规模;二、农业、工业的演变趋势与投资对策;三、自然因素与社会因素的均衡状态探索。     

COSMOS/M 有限元程序在 Tokamak 装置设计中的应用

概述了有限元技术及其在Ｔｏｋａｍａｋ装置工程设计中应用的最新发展动态。对新一代面向微型计算机的大型结构有限元分析程序ＣＯＳＭＯＳ／Ｍ作了较全面的剖析，并给出了应用该程序对核聚变实验装置中大型机械结构强度分析的应用实例。     

我国R＆D投入对区域经济发展影响的实证研究

本文利用DEA方法,选取年末就业人数、研发投入（R＆D）、资本形成总额为输入指标,地区生产总值为输出指标,对2001～2010年全国各省市区域经济的生产效率及Malmquist生产力指数进行测算。在生产效率方面,全国平均生产效率为0．7;5,显示出我国整体经济效率还存在27％的改善空间,造成整体无效率的原因主要是规模无效率,显示出我国对于现有技术的合理配置和使用存在问题,应加强对现有技术的优化配置和合理利用。在生产力变动方面,就全国平均malmquist指数而言,技术进步是导致TFP值增长或损失的主要影响因素。